This invention is related to water-saving toilet-flushing mechanisms and in particular to dual-level evacuation pipes and related water-flow control for flushing toilet tanks.
Current flushing toilets use excessive amounts of water whenever flushed, particularly for liquid wastes. In fact, present toilets use approximately five (5) gallons per flush regardless of the amount of water needed to properly flush the toilet. A variety of dual-level evacuation pipes have been Examples known by Applicant include the following U.S. Pat. Nos.:
4,353,138 Bell (1982) PA0 4,175,295 Cameron (1979) PA0 4,172,299 del Poze (1979) PA0 4,122,564 Addicks et al. (1978) PA0 4,042,982 Contreras (1977) PA0 3,903,551 Johnson (1975) PA0 3,768,103 Robinson (1973) PA0 1,963,211 Patterson (1934)
All of these patents have contributed to understanding problems involved in minimizing water used for flushing toilets. However, none has been sufficiently convenient and low-cost to become widely used. The first water-saving toilet patented with a dual-level evacuation pipe was in 1934. Under the circumstances at that time, minimizing water-use to prevent filling sewage tanks and drain fields was a problem. In effect, the waste-disposal problem of the world has become similar in ways to localized sewage-tank and drain-field conditions of several generations previous. Civilization is repeating itself. Now again, the need is urgent. Both state and federal legislation are being considered for demanding water-saving toilet flushers and a search is on for the most economical, convenient and reliable one.
The objective of a dual-level evacuation column or pipe is to provide a full tank for flushing solids from the toilet bowl and to provide a partial tank of water for flushing liquids and other light flushing loads. In comparison to the known prior art, applicant's dual-level evacuation column provides for a larger outlet orifice immediately above a pipe leading from the flushing tank to the toilet bowl. This diminishes water resistance and makes it possible to get a good flush with the least amount of water as a result of fast inflow of water into the toilet bowl. It can be adapted at lower cost for parts and for labor either to adapt existing toilets or to produce them initially. It also provides for minimizing the amount of water used for filling a toilet bowl to a level that seals out sewage-pipe odors at the vertical outlet curve in the drain pipe. These are substantial advantages in light of how much advancement is required to prompt change, even when the need is great.
The Patterson patent granted in 1934 was costly, complicated and required a manual pulling of a flush handle outwardly from the water tank in addition to the turning of the flush handle either upwards for light flushing or downward for full flushing. The Bell U.S. Pat. No. 4,353,138, granted in 1982 was relatively simple but required a new handle adaptation that is not required by the applicant's dual-level flushing mechanism. The Cameron U.S. Pat. No. 4,175,295, 1979, was very simple and reliable, but it too required new handle means and it did not have a direct outlet of water that would facilitate flushing with the least amount of water. The del Pozo U.S. Pat. No. 4,172,299, 1979, came closer to the present invention, but did not achieve providing a direct outlet of water above the tank outlet pipe and it also was very simple, but it too required a new handle mechanism for its installation and it operated differently than applicant's device. The Addicks et al. U.S. Pat. No. 4,122,564, 1978, operated differently than applicant's device in that a lower-level outlet valve was actuated by a lever at the opposite side of a fulcrum from the valve by upward rotational movement of the handle and the top valve was operated conventionally. Other patents mentioned above and still others known of are constructed differently than applicant's device. These prior such devices are more expensive to retrofit or to construct initially and are less advantageous for encouragement of their use.